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基于光学相机的光流-相机定标融合定位算法

北京邮电大学学报 2024年第1期47卷 100-105,119页

作者：苑振博白勃罗柳君张晓薇尚韬西安电子科技大学通信工程学院西安710071

为了解决光流算法在相机大转角情况下定位误差过大和相机定标定位算法在LeD数量不足的情况下无法定位的问题,提出将相机定标定位算法和光流算法进行卡尔曼滤波融合的光流-相机定标融合定位算法。首先,采用相机定标定位算法进行室内定位... 详细信息

为了解决光流算法在相机大转角情况下定位误差过大和相机定标定位算法在LeD数量不足的情况下无法定位的问题,提出将相机定标定位算法和光流算法进行卡尔曼滤波融合的光流-相机定标融合定位算法。首先,采用相机定标定位算法进行室内定位;其次,引入光流算法补偿相机定标定位算法的计算结果;最后,采用卡尔曼滤波融合2种算法的定位结果。搭建实验平台验证所提算法的定位性能。实验结果表明,所提算法能够解决相机定标定位算法在LeD数量不足的情况下无法定位的问题,同时能够克服光流算法在相机大转角情况下定位误差过大的问题,将相机在大转角运动情况下平均定位误差从6.86 cm降低至1.02 cm。

关键词：相机定标定位算法光流算法卡尔曼滤波准确性鲁棒性

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水氮耦合对枸杞冠层结构及产量的影响

节水灌溉 2024年第7期 24-32页

作者：王彦军马波管恩晴杨艳宁夏大学土木与水利工程学院银川750021 宁夏节水灌溉与水资源调控工程技术研究中心银川750021 教育部旱区现代农业水资源高效利用工程研究中心银川750021

为探明水氮耦合对枸杞冠层结构及产量的影响,揭示枸杞冠层结构与蒸散、氮消耗的互馈机制,于2014-2015年以4 a树龄的“宁杞1号”为研究对象,设置4个水平灌溉定额(W1:2277 m^(3)/hm^(2)、W2:2593 m^(3)/hm^(2)、W3:2856 m^(3)/hm^(2)及W4:... 详细信息

为探明水氮耦合对枸杞冠层结构及产量的影响,揭示枸杞冠层结构与蒸散、氮消耗的互馈机制,于2014-2015年以4 a树龄的“宁杞1号”为研究对象,设置4个水平灌溉定额(W1:2277 m^(3)/hm^(2)、W2:2593 m^(3)/hm^(2)、W3:2856 m^(3)/hm^(2)及W4:3160 m^(3)/hm^(2))及3个水平施氮量(2014年N1:501 kg/hm^(2)、N2:668 kg/hm^(2)及N3:860 kg/hm^(2);2015年N1:620 kg/hm^(2)、N2:854 kg/hm^(2)及N3:1092 kg/hm^(2)),对比分析不同水、氮条件对枸杞冠层结构及产量的影响。结果表明:2 a均表明W3N2处理枸杞叶面积指数(LAI)和平均叶倾角(MTA)较大,其中LAI为2.46(2014年)和2.86(2015年),较其他处理(除2015年W2N1外)提高了2.9%~80.1%(2014年)和4.7%~48.9%(2015年),MTA为45°(2014年)和50°(2015年),较其他处理增加了7.1%~40.6%(2014年)和6.4%~28.2%(2015年),该处理透射率(DIFN)在各处理中居中,介于0.25~0.35;2 a试验结果均W3N2处理产量最高,分别为2599.9 kg/hm^(2)(2014)和4621.7 kg/hm^(2)(2015),与其他处理相比提高了42.5%~65.7%(2014)和0.5%~15.9%(2015);蒸散量(eT_(a))随LAI和MTA增加而增加,但LAI超过3时,就会抑制冠层蒸散;LAI趋于3、MTA和DIFN分别介于45°~50°和0.25~0.35时,枸杞碱解氮消耗较大,2014年和2015年分别为883.4 kg/hm^(2)和1001.1 kg/hm^(2)。综合分析,在枸杞理想冠层和最大产量目标下,灌溉定额为2856 m^(3)/hm^(2),4 a树龄施氮量为668 kg/hm^(2),5 a树龄施氮量为854 kg/hm^(2),有利于枸杞冠层结构生长发育且会获得理想的产量,研究结果可为宁夏枸杞水肥管理及冠层结构调整提供理论依据。

关键词：水氮耦合枸杞冠层结构耗水过程产量蒸散量

Digestive and breast cancer patients managed during the first wave of COVID-19 pandemic:Short and middle term outcomes

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World Journal of Methodology 2024年第2期14卷 107-126页

作者： Jacobo Trébol.Ana carabias-Orgaz María carmen esteban-Velasco Asunción García-Plaza Juan Ignacio González-Munoz Ana Belén Sánchez-casado Felipe carlos Parreno-Manchado Marta eguía-Larrea José Antonio Alcázar-Montero Cirugía General y del Aparato Digestivo Complejo Asistencial Universitario de SalamancaSalamanca 37007SalamancaSpain Cirugía Universidad de SalamancaSalamanca 37007SalamancaSpain Oftalmología Complejo Asistencial Universitario de SalamancaSalamanca 37007SalamancaSpain

BACKGROUND The first wave of coronavirus disease 2019(COVID-19)pandemic in Spain lasted from middle March to the end of June *** population was subjected to lockdown periods and scheduled surgeries were discontinued or reduced during variable *** our centre,we managed patients previously and newly diagnosed with *** established a strategy based on limiting perioperative social contacts,preoperative screening(symptoms and reverse transcriptionpolymerase chain reaction)and creating separated in-hospital COVID-19-free pathways for non-infected *** also adopted some practice modifications(surgery in different facilities,changes in staff and guidelines,using continuously changing personal protective equipment…),that supposed new *** To analyse cancer patients with a decision for surgery managed during the first wave,focalizing on outcomes and pandemic-related *** We prospectively included adults with a confirmed diagnosis of colorectal,oesophago-gastric,liver-pancreatic or breast cancer with a decision for surgery,regardless of whether they ultimately underwent *** analysed short-term outcomes[30-d postoperative morbimortality and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection]and outcomes after 3 years(adjuvant therapies,oncological events,death,SARS-CoV-2 infection and vaccination).We also investigated modifications to usual *** From 96 included patients,seven didn’t receive treatment that period and four never(3 due to COVID-19).Operated patients:28 colon and 21 rectal cancers;laparoscopy 53.6%/90.0%,mortality 3.57%/0%,major complications 7.04%/25.00%,anastomotic leaks 0%/5.00%,3-years disease-free survival(DFS)82.14%/52.4%and overall survival(OS)78.57%/76.2%.Six liver metastases and six pancreatic cancers:no mortality,one major complication,three grade A/B liver failures,one bile leak;3-year DFS 0%/33.3%and OS 50.0%/33.3%(liver metastases/pancreatic carcinoma).5 g

关键词： COVID-19 SARS-CoV-2 Colon cancer rectal cancer Breast cancer Liver cancer Pancreatic cancer Gastric cancer Oesophageal cancer Surgery

High responsivity and Ultra-Low Detection Limits in Nonlinear a-Si:H p-i-n Photodiodes enabled by Photogating

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Photonic Sensors 2023年第4期13卷 27-38页

作者： Andreas BABLICH Maurice MÜLLeR Rainer BORNeMANN Andreas NACHTIGAL Peter HARING bol.VAR Institute of Graphene-Based Nanotechnology University of SiegenHölderlinstr.357076 SiegenGermany Institute of High Frequency and Quantum electronics University of SiegenHölderlinstr.357076 SiegenGermany

Photodetectors operating at the wavelength in the visible spectrum are key components in high-performance optoelectronic *** this work,massive nonlinearities in amorphous silicon p-i-n photodiodes enabled by the photogating are presented,resulting in responsivities up to 744 mA/W at blue *** detectors exhibit significant responsivity gains at optical modulation frequencies exceeding MHz and a more than 60-fold enhanced spectral response compared to the non-gated *** detection limits down to 10.4 nW/mm^(2) and mean signal-to-noise ratio enhancements of 8.5dB are demonstrated by illuminating the sensor with an additional 6.6μW/mm^(2) red ***-optical simulations verify photocarrier modulation due to defect-induced field screening to be the origin of such high responsivity *** experimental results validate the theory and enable the development of commercially viable and complementary metal oxide semiconductor(CMOS)compatible high responsivity photodetectors operating in the visible range for low-light level imaging and detection.

关键词： Photogating amorphous silicon a-Si:H nonlinearity photodetector responsivity gain

Wear behavior of the raw and pre-smashed carbon nanotubes reinforced 6061Al composites fabricated by powder metallurgy

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Science China(Technological Sciences) 2022年第5期65卷 1149-1159页

作者： LI XiaoNan LIU ZhenYu ZAN YuNing XIAO bol. NI DingRui WANG QuanZhao WANG Dong MA ZongYi Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and engineering University of Science and Technology of ChinaShenyang110016China

The raw and pre-smashed(PS)carbon nanotube(CNT)reinforced 6061Al composites(CNT/6061Al)with different CNT contents were respectively fabricated by powder metallurgy *** was found that reducing the CNT cluster size by presmashing processing could sharply reduce the friction coefficient,and significantly improve the density,hardness,and wear resistance of the CNT/6061Al *** the raw-CNT/6061Al composites,the wear rate increased approximately linear trend while the CNT content was over 1 wt.%.The plastic deformation,deep grooves,and serious delamination were presented on the wear *** wear process was gradually transformed from Al-copper base counterpart wear into Al-Al wear for the higher adhesion-binding energy between aluminum and copper base *** for the PS-CNT/6061Al composites,the wear rate gradually decreased as the CNT content increased from 0 to 2 wt.%.This was mainly because the generation of the thinner mechanically mixed layer(MML)and the PS-CNT prevented the direct contact between specimen and copper base counterpart,which effectively inhibited the adhesive *** excessive PS-CNTaddition(~3 wt.%)would weaken the bonding between CNT and 6061Al,and thus the wear resistance of the composite was reduced apparently.

关键词： wear carbon nanotube aluminum matrix composites clustering

CO_(2)emission and source partitioning from carbonate and non-carbonate soils during incubation

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Pedosphere 2022年第3期32卷 452-462页

作者： Yi ZHAO Roland bol.Zhaoan SUN Yuping ZHUGe Xiaoxia SHI Wenliang WU Fanqiao MeNG Beijing Key Laboratory of Biodiversity and Organic Farming College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193(China) Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum Jülich GmbHJülich 52425(Germany) Key Laboratory of Biology and Molecular Biology in University of Shandong College of Biological and Agricultural EngineeringWeifang UniversityWeifang 261061(China) National engineering Laboratory for efficient Utilization of Soil and Fertilizer resources College of Resources and EnvironmentShandong Agricultural UniversityTai'an 271018(China) Sinocarbon Innovation&Investment Jiangsu Co. Ltd.(SCII)Nanjing 210046(China)

The accurate quantification and source partitioning of CO_(2)emitted from carbonate(i.e.,Haplustalf)and non-carbonate(i.e.,Hapludult)soils are critically important for understanding terrestrial carbon(C)*** two main methods to capture CO_(2)released from soils are the alkali trap method and the direct gas sampling method.A 25-d laboratory incubation experiment was conducted to compare the efficacies of these two methods to analyze CO_(2)emissions from the non-carbonate and carbonate-rich *** isotopic fraction was introduced into the calculations to determine the impacts on partitioning of the sources of CO_(2)into soil organic carbon(SOC)and soil inorganic carbon(SIC)and into C3 and/or C4 plant-derived *** results indicated that CO_(2)emissions from the non-carbonate soil measured using the alkali trap and gas sampling methods were not significantly *** the carbonate-rich soil,the CO_(2)emission measured using the alkali trap method was significantly higher than that measured using the gas sampling method from the 14 th day of incubation *** SOC and SIC each accounted for about 50%of total soil C in the carbonate-rich soil,SOC decomposition contributed 57%–72%of the total CO_(2)*** both non-carbonate and carbonate-rich soils,the SOC derived from C4 plants decomposed faster than that originated from C3 *** propose that for carbonate soil,CO_(2)emission may be overestimated using the alkali trap method because of decreasing CO_(2)pressure within the incubation jar,but underestimated using the direct gas sampling *** gas sampling interval and ambient air may be important sources of error,and steps should be taken to mitigate errors related to these factors in soil incubation and CO_(2)quantification studies.

关键词： alkali trap C3/C4 plant inorganic carbon stock isotope fractionation organic carbon stock

Spatial-temporal variations and driving factors of soil organic carbon in forest ecosystems of Northeast China

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Forest ecosystems 2023年第2期10卷 141-152页

作者： Shuai Wang bol.Roland Kabindra Adhikari Qianlai Zhuang Xinxin Jin Chunlan Han Fengkui Qian College of Land and environment Shenyang Agricultural UniversityShenyang110866China Key Laboratory of ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum Jülich GmbHWilhelm-Johnen-Straße52428JülichGermany School of Natural Sciences Environment Centre WalesBangor UniversityBangorLL572UWUK USDA-ARS GrasslandSoil and Water Research LaboratoryTempleTX76502USA Department of earth Atmosphericand Planetary SciencesPurdue UniversityWest LafayetteIN47907USA

Forest soil carbon is a major carbon pool of terrestrial ecosystems,and accurate estimation of soil organic carbon(SOC)stocks in forest ecosystems is rather *** study compared the prediction performance of three empirical model approaches namely,regression kriging(RK),multiple stepwise regression(MSR),random forest(RF),and boosted regression trees(BRT)to predict SOC stocks in Northeast China for 1990 and ***,the spatial variation of SOC stocks and the main controlling environmental factors during the past 25 years were identified.A total of 82(in 1990)and 157(in 2015)topsoil(0–20 cm)samples with 12 environmental factors(soil property,climate,topography and biology)were selected for model *** selected80%of the soil sample data were used to train the models and the other 20%data for model verification using mean absolute error,root mean square error,coefficient of determination and Lin's consistency correlation coefficient *** found BRT model as the best prediction model and it could explain 67%and 60%spatial variation of SOC stocks,in 1990,and 2015,*** maps of all models in both periods showed similar spatial distribution characteristics,with the lower SOC in northeast and higher SOC in *** annual temperature and elevation were the key environmental factors influencing the spatial variation of SOC stock in both *** stocks were mainly stored under cambosols,Gleyosols and Isohumosols,accounting for 95.6%(1990)and 95.9%(2015).Overall,SOC stocks increased by 471 Tg C during the past 25 *** study found that the BRT model employing common environmental factors was the most robust method for forest topsoil SOC stocks *** spatial resolution of BRT model enabled us to pinpoint in which areas of Northeast China that new forest tree planting would be most effective for enhancing forest C ***,our approach is likely to be useful in forestry management and ecologic

关键词： Soil organic carbon stocks Forest ecosystem Spatial-temporal variation carbon sink Digital soil mapping

Mechanical properties of(B_(4)C+Al_(2)O_(3))/Al neutron absorbing materials with various microstructures constructed by hot forging,rolling and extrusion

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Science China(Technological Sciences) 2022年第5期65卷 1206-1209页

作者： ZAN YuNing LI XinNan ZHOU Cong LIU ZhenYu WANG QuanZhao XIAO bol. MA ZongYi Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Nuclear equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing100840China

Neutron absorbing materials(NAMs)are necessary in the nuclear industry for the storage and transportation of spent *** all the NAMs,B_(4)C/Al composites are widely used because of the specific neutron absorption capacity[1–4].Compared with traditional low-strength functional NAMs such as B_(4)C/1100Al and B_(4)C/6061Al,NAMs with enough high-temperature(350℃)strength are competent for further structural usage and exhibit huge advantages in the dry storage of spent fuel because of heat transfer ability and weight reduction[5].

关键词： absorbing strength enough

深冷循环对SiC/Al复合材料宏微观残余应力的影响

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金属学报 2024年第8期60卷 1031-1042页

作者：谷黎明冯效铭于朝张峻凡刘振宇何伦华卢怀乐李小虎王晨张晓东肖伯律马宗义中国科学院金属研究所、师昌绪先进材料创新中心沈阳110016 中国科学技术大学、材料科学与工程学院沈阳110016 散裂中子源科学中心东莞523803 中国科学院物理研究所、北京凝聚态物理国家研究中心北京100190 松山湖材料实验室东莞523808 中国科学院高能物理研究所北京100049

铝基碳化硅(SiC/Al)复合材料因其高比模量、高比强度和良好尺寸稳定性等特点广泛应用于精密光学领域。SiC/Al复合材料热处理过程中产生的宏/微观残余应力是影响其尺寸稳定性的关键因素。为了阐明残余应力的降低方法和效果,提高精密光学... 详细信息

铝基碳化硅(SiC/Al)复合材料因其高比模量、高比强度和良好尺寸稳定性等特点广泛应用于精密光学领域。SiC/Al复合材料热处理过程中产生的宏/微观残余应力是影响其尺寸稳定性的关键因素。为了阐明残余应力的降低方法和效果,提高精密光学零件的尺寸稳定性,本工作使用中子衍射和有限元模拟,分析了深冷循环处理对于体积分数为35%的SiC/6092Al复合材料在退火状态下宏微观残余应力的影响,研究了深冷循环次数、样品尺寸、增强相颗粒尺寸和深冷循环温度差等影响因素。结果表明,深冷循环能引起基体塑性应变,从而显著降低退火态SiC/Al复合材料的相应力,并且随着深冷循环次数的增加,单次循环相应力降低效果减弱。深冷循环导致的塑性应变集中在颗粒周围的基体,主要影响颗粒和周围基体的相应力大小,与样品尺寸无明显关联,并且深冷循环不增加退火态样品的宏观残余应力。复合材料多次深冷循环后的相应力降低量与SiC颗粒尺寸无关,并且,多次深冷循环对相应力的降低效果与深冷循环温度差关系较小,100~-196℃和200~-196℃进行多次深冷循环对相应力的改变十分接近。

关键词：深冷循环中子衍射残余应力有限元方法代表性体积单元

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